The present invention generally relates to an electrical charging arrangement and more particularly, to an electrical charging apparatus for imparting electrical charge through a surface creepage or creeping discharge.
Generally, in an electrical charging apparatus arranged to impart electrical charge through corona discharge, a large amount of ozone is produced thereby during its electrical discharging, and it is known that ozone as referred to above not only deteriorates a photosensitive member or photoreceptor of an electrophotographic copying apparatus and the like, but also is harmful to human bodies. In order to overcome the disadvantages as described above, there have conventionally been proposed, for example, in Japanese Patent Laid-Open Publication Tokkaisho No. 56-154759, electrical charging devices (or corona discharging devices) as shown in FIGS. 1 through 4 in which a plurality of heating members 5, 6, 6' and 8 are respectively provided in the vicinity of corona electrodes 1 for thermal decomposition of ozone produced near the corona electrodes 1.
However, in the known devices as described above, since heating temperatures of the heating members 5, 6, 6' and 8 are set in the range of 200.degree. to 300.degree. C., the corona electrodes 1 tend to be expanded by the heat, thus resulting in non-uniformity of discharging characteristics. Meanwhile, when the electrical charging devices as described above are employed for an electrophotographic copying apparatus, there are such disadvantages that deterioration of a photosensitive member or photoreceptor and fusion of toner, etc. take place by the heat radiated by the heating members 5, 6, 6' and 8, with a further increase of power consumption.
For solving the various problems as referred to above, it may be considered to suppress the heat values of the heating members 5, 6, 6' and 8. However, when the heating temperatures thereof are lowered, although part of ozone may be subjected to thermal decomposition by the heating members 5, 6, 6' and 8, some other part of ozone passes between the respective heating members without being decomposed, thus resulting in a low ozone decomposing efficiency.